Mounting means for boat propulsion



Jan.'29; 1963 T. G. LANG I 7 MOUNTING MEANS FOR BOAT PROPULSION Filed Nov. 19, 1959 2 Sheets-Sheet 1 (ammo THOMAS G. LANG,

INVENTOR.

Attorn ys ll MM HERZIG 8: J'ESSUP Jan. 29, 1963 'r. s. LANG 3,075,490

MOUNTING MEANS FOR BOAT PROPULSION Filed Nov. 19, 1959 2 She ets Sheet 2 IILIIIIIII II... Illh g THOMAS G. LANG,

INVENTOR.

HERZIG 8: JESSUP, Attorneys ZJWT 9 4 State 3 075,420 MOUNTING MEAN FOR BOAT PROPULSION Thomas G. Lang, Arcadia, Calif. (1777 Grevelia St., Apt. J, South Pasadena, Calif.) Filed Nov. 19, 1959, Ser. No. 854,103 4 Claims. (Cl. 115-41) tion so the propeller remains submerged after the boat matically raises the motor when the boat stops in order rises above the water on its hydrofoils and which autoto protect the motor from waves.

Another object is to provide means for automatically Other objects are to provide an exterior mounting for an outboard motor to enable a higher transom to be used on a boat, to provide more room in the boat, to provide more quiet operation of the motor, and to eliminate gas and oil leakage from the motor.

Another object is to automatically tilt the propeller shaft at the lower motor speeds so the propeller operates less efiiciently, thereby permitting slower trolling speeds for fishing.

Another object is to provide means for adjusting the lowest operating position of the propeller for most efiicient high speed operation.

Another object is to provide a mounting means for an outboard motor which can be easily attached to a boat transom and which can be economically manufactured.

Other objects and advantages of the invention will be apparent from the following description.

In the accompanying drawings, forming a part of this specification, and in which like numerals are employed to designate like parts throughout the same:

FIGURE 1 is a perspective view of a mounting for an outboard motor attached to the transom of a boat.

FIGURE 2 is a side elevation of the motor mount including the outboard motor illustrating the upper position thereof.

FIGURE 3 is atsectional view of a biasing means combined withadjustable stops and a shock absorber.

FIGURE 4 is a side elevation of an alternate construction of the motor mount.

FIGURE 5 is a side elevation of a hydrofoil boat equipped with the means of this invention and with an outboard motor, illustrating the lower, operating position.

FIGURE 6 is a perspective view of the deflection plate shown in FIGURES 1 and 2.

Referring more particularly to the drawings, the numeral 2 refers to a support member which is adapted to have an outboard motor mounted thereto and consisting of a pair of triangular brackets 2a spanned by a transverse board 2b. Member 2 is pivotally mounted to brackets 3 by means of pivot bolts 4 in such a manner that it is free to pivot about a pivot axis joining pivot bolts 4. Brackets 3 are attachable to boat transom 6 by suitable means as bolts 3a that hold the brackets rigidly to the transom. The lower pivotal position of the support member 2 is limited by a lower stop means such as the nuts 7 which contact a truss of the brackets 2a. Nuts 7 are screwed on eye bolts 8 in such a manner that their position is adjustable. The eyes of the eye bolts 8 are pivotally attached to brackets 3 by bolts 9, and the arms of the eye bolts freely pass through holes 11 in the trusses of brackets 2a. Other means could be used to limit the lower position of the support member 2 such as cables 26 (FIG. 4) attached between points 9 and 11.

Tension springs 12 are shown attached between the upper part of support member 2 and the upper part of brackets 3 in order to bias support member 2 pivotally toward an upper position. The tension in springs 12 decreases as the support member 2 pivots upward, such that when an outboard motor is attached to support member 2 an upper equilibrium position is reached where the spring 2. The propeller 13 of outboard motor 14 exerts a thrust along its axis 10 which passes below pivot bolts 4. This produces a new moment about pivot bolts 4 which tends to pivot support member 2 downward until springs 12 stretch sufiiciently so their tension is increased to balance the thrust or until support member 2 contacts lower stops 7. The position of the support member in the latter I case is shown in FIGURE 5. In practice, the spring bias will normally be designed such that the support member will rest in its lower position for medium to high values of propeller thrust and move upward only when the thrust is small or zero. In this manner the boat.

In some cases it may be found convenient to limit 1 the upper position of pivoting of support member 2 by an upper stop means such as nuts 16 screwed on eye bolts 8. creased such that support member 2 will remain fixed in an upper position resting against nut 16 until a certain minimum thrust is exceeded and with slight increased thrust will then rest against the lower stop nuts 7, thereby providing effectively only an upper-and a lower position of the motor and propeller, the lower position corresponding to higher speed operation.

It will be seen that the motor mount of this present invention provides automatic raising and lowering of the outboard motor and propeller. a boat is normally low when the boat is operating near shore or is navigating in treacherous waters; in these cases my invention automatically raises the propeller to mini-' mize its chances of being damaged. It must be recognized that at least a portion of the propeller 13, and

preferably all of it must be in the water in all positions desirable to maintain as much height of the motor above the waves as possible when the boat is at rest or moving very slowly. At higher boat speeds, a trough is formed behind the boat transom which lowers the water surface, permitting the motor to be safely lowered, which is automatically effected by my invention. Also, even at low forward speeds, the motor will be protected to a great extent from waves by the boat itself, so the springs 12 can be designed to automatically lower the motor at relatively low thrusts.

It is evident that any propeller means could be mounted similarly to that of the outboard motor propeller 13 in FIGURE 2 in such a manner as to be automatically lowered by action of its thrust. It has been found that struts of many outboard motors have relatively wide sections Patented Jan. 29, 1953 In this case the bias of springs 12 can be in- The propeller thrust of a few inches ahove their cavitation plates in order to house shock mounts, shaft bearings, and the like, which would tend to deflect large amounts of water when moving forward, since these sections would extend below the. support member 2'. It has been found desirable, therefore, to attach a wedge-shaped (in plan form) deflection plate 17 to the lower side of support member 2' to split the Water so it passes on either side of the motor strut. An inclined. plate (inside veiw) has sometimes been found unsatisfactory because of its tendency to. plane and produce upward oscillatingforces when the boat passes through waves which thereby: forces. the support member 2 to pivot away from and" then against lower stop member 7 in an objectionable manner. This oscillation can be eliminated by the use of deflection plate 17 or the addition of a shock absorber 18', shown schematically in FIGURE 2 attached between brackets 3" and support member 2 or by means of a latch that auto matically locks support member 2 in the lower position duringhigh speed operation. The shock absorber 18 may also be conveniently used to cushion the movementsv of support member 2 when it moves awayfrom or toward upper stopnuts 16 and lower stop nuts 7.

An alternate method of construction of the biasing means, stops,. and shock absorber is schematically shown in- FIGURE 3, wherein a spring 12a is placed in compression betweenend of cyl-iner 19' and piston 21'; piston. 21 is attached to rod-22, which in turn is pivotallybolte'd to support member 2 near its upper edge. Cylinder 19 ispivotally attached to bracket 3'. A nut 23 is screwed on rod 22 to provide upper stop means, and peg 24 is positioned in cylinder 19, to provide lower stop means to limit the oscillation of support member 2. Cylinder 19 can be filled with a viscous fluid and the piston provided with an orifice= 21a to thereby act as the aforementioned shock absorber.

Another alternate construction is shown in FIGURE 4, wherein the support' member 2 is pivotally mounted to brackets 3- near their upper end, and-a spring'12c is placed in compression between end of cylinder 19aand elongated piston 21b, which in turn" is pivotally attached to support member 2. The left end of cylinder 19a is pivotally attached to bracket 3; The lower stop means in this caseconsists of peg 24a placed through piston 21]) and the upper stop means consists'of cable 26 attached between bracket 3- and support member 2. In this alternate constructionthe main advantageis that the support member 2 can be pivoted to a' position almostwithin the boat (shown in dotted lines), uponrelease of cable 26 and cylinder: 19a from bracket 3, in order torepair-"the-motor or; propeller while. at sea without having to remove the motor from support member 2.

An important use of this novel invention is in combination with a hydrofoil boat shown in operation in FIGURE 5. As the boat 27- gains speed, it rises on its hydrofoils 28, ina manner well known by those skilled in; the art. An: outboard boat having hydrofoils may risefrom a few inches to over a foot above the wateronits-hydrofoils at higher speeds. Consequently, if a conventional short shaft outboard motor is to be utilized for propulsiomit must be: lowered withrespect to the boat to keep its propeller submerged at these higher speeds. At lower speeds, when the boat once again contacts the water, the motor must be raised again so it will not be damaged by waves. Consequently, the mounting means for boat propulsion. described herein is uniquely suited for use with a hydrofoil craft. Such a craft is illustrated for example in my co-pending application Serial No. 854,176, filed November 19-, 1959 entitled Hydrofoil for Water Craft. If it is. desired to supply a kit composed of hydrofoils' adapted to be attached to a. conventional outboard boat, to-convert it. into. a hydrofoil craft, the outboard. mot-or. mount describedhereinisv ideally suited for use. with. or. inclusion with. such a kit, since the. smaller. outboard. motor boatsv are powered by conventional short shaft motors.

I. claim as. my invention:

1.. Mounting means for av boat propulsion mechanism having, a rotary propeller, comprising: means defining a transverse, generally horizontalaxis on: a. boat transom adjacent the bottom thereof; a bracket pivotally mounted on said transom. about said axis, said bracket extending rearwardly and" generally horizontally from said axisand having amounting portion. thereon adjacent. therear end thereof, propulsion. meanshaving. a propeller mounted onsaid mounting portion to. rotate, on a foreand-aft axis. passing. below said transverse axis; thehorizontal distance from said transverse axis. to. said. propeller being at least about equal. to the vertical distance between said transverse axis and. said fore-and-aft axis whereby said propeller moves generally vertically downa wardly as. said bracket pivots about said. transverse. axis in response to forward thrust of. said. propeller.

2'. Mounting meansas defined in claim 1- including.

resilient means urging said bracket to swing upwardly to normally counterbalance. the weight of saidbracket andpropulsion means but yi eldable to permitsaid bracket to swing downwardly by forward. thrust. developed by. said propellen.

3. Mounting means as defined in claim 1 wherein said mounting portion comprises. an'upright board for remo.v ably mounting an outboard motor.

4. Mounting means as defined inclaim l includingv means limiting the range of movement of. said bracket about said transverse axis. to a sector. wherein the motion of said propeller isprincipally vertical.

References Cited inthe file of this patent UNITED STATES. PATENTS 2,713,843 Staley July 26, 1955. 2,748,743- Shogran Iune'5, .1'956 2,749,869 Bush June 12-, 1956: 2,782,744 Staley Feb. 26, 1957 2,795,202. Hook. June. 11', 1957 2,856,877 Baker Oct. 21, 1958 2,886,462 Iagiel May 12, 1959 2,916,009 Baird Dec. 8, '1959 FOREIGN PATENTSv 484,373 Italy Sept. 8, 1953 

1. MOUNTING MEANS FOR A BOAT PROPULSION MECHANISM HAVING A ROTARY PROPELLER, COMPRISING: MEANS DEFINING A TRANSVERSE, GENERALLY HORIZONTAL AXIS ON A BOAT TRANSOM ADJACENT THE BOTTOM THEREOF; A BRACKET PIVOTALLY MOUNTED ON SAID TRANSOM ABOUT SAID AXIS, SAID BRACKET EXTENDING REARWARDLY AND GENERALLY HORIZONTALLY FROM SAID AXIS AND HAVING A MOUNTING PORTION THEREON ADJACENT THE REAR END THEREOF; PROPULSION MEANS HAVING A PROPELLER MOUNTED ON SAID MOUNTING PORTION TO ROTATE ON A FOREAND-AFT AXIS PASSING BELOW SAID TRANSVERSE AXIS; THE HORIZONTAL DISTANCE FROM SAID TRANSVERSE AXIS TO SAID PROPELLER BEING AT LEAST ABOUT EQUAL TO THE VERTICAL DISTANCE BETWEEN SAID TRANSVERSE AXIS AND SAID FORE-AND-AFT AXIS WHEREBY SAID PROPELLER MOVES GENERALLY VRITICALLY DOWNWARDLY AS SAID BRACKET PIVOTS ABOUT SAID TRANSVERSE AXIS IN RESPONSE TO FORWARD THRUST OF SAID PROPELLER. 